Scraper for bands with a sensitive surface



SCRAPER FOR BANDS WITH A SENSITIVE SURFACE Filed Nov. 28, 1954 Fig.1

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Patented Aug. 11, 1936 UNITED STATES PATENT OFFICE.

Ernest Bleibler, Ghent, Belgium, assignor to Sylvania IndustrialCorporation, Fredericksburg, Va., a. corporation of Virginia ApplicationNovember 28, 1934, Serial No. 755,244 In Great Britain November 28, 19334 Claims.

This in ention relates in general to an apparatus for treating with aliquid sheets or films in the form of endless bands or in continuouslengths, and in particular, to such an apparatus having a scraperadapted to remove surplus liquid from the surface of such sheets orfilms.

It is an object of this invention to arrange the scraper so as to removein a substantially complete way the liquid which the band might conveyfrom one bath to the next.

It is a further object of this invention to vary and adjust within verywide limits the pressure, without there being any risk of the sheets orfilms with the sensitive or delicate surface being crushed or creased orthere being any fear that the band may be damaged in any other way, asby the formation of streaks, scratches or the like.

According to the invention there is provided an apparatus for treatingsheets or films with a liquid or liquids which comprises the combinationof a treating vat containing a liquid, means to pass the sheet or filmthrough the liquid in the vat, and a scraper positioned above the levelof the liquid, the scraper comprising a pair of rotatable, preferablycylindrical, wiping members, means to support the wiping members inspaced parallel relation and means adjustable for positioning thesemembers in wiping contact with a sheet or film passing between thewiping members. Where the sheet or film is especially fragile or has adelicate surface, the scraper may be further provided with means forresiliently holding the wiping members in contact with the surface ofthe sheet or film to avoid crushing or damaging the surface in any way.

The bars may be made of any material chemically inert to the wet film orto the baths, suitable materials being glass, porcelain or metal, wood,stone or artificial masses such as resins and the like.

The invention will be best understood on re? ferring to the drawingafiixed to my specification and forming part thereof which illustratesthe invention as embodied in a preferred construction. It will bereadily understood, however, that my invention is by no means limited tothis construction and that the scope of my invention and the ambit of myappended claims extends to any construction incorporating the broadprinciple underlying my invention.

In the drawing:

Fig. 1 shows in transverse section the arrangement of the new scraper inthe operative position on the band between two treatment baths.

56 Fig. 2 shows the scraper in the open position,

Fig. 3 is a front elevation of the scraper, while Figs. 4 and 5 are sideelevations of arrangements for fixing the scraper in position in anadjustable and resilient manner.

Two successive baths are denoted by H and 6 l2 through which a band l3to be treated, principally one with a sensitive surface, is' passedcontinuously. The scraper 20 is placed between 'the successive baths. Itconsists of two bars 2|,

22 which run parallel with each other at a disl0 tance from each otherand the endless band I3 is threaded between them. The bars are mountedto rotate, preferably freely, between suitable heads or flanges 25, 26which are carried in their turn on shafts or spindles 35, 36 which 15are rotatably mounted in suitable bearings 21', 28, as indicateddiagrammatically in Fig. 3.

Fig. 2 shows the scraper in the open position in which the band isthreaded through it. By rotating it in the direction indicated by thear- 20 row, the scraper is brought into the operative position, in whichthe underside of the band bears against one scraper 2| and the top ofthe band against the other scraper 22. According to the pressure withwhich the bars are held 25 against the band, the pressure of the scrapercan be regulated as may be desired. As this pressure can be altered toany degree of fineness by slightly altering the angle which the contactsurface of the two spindles of the bars makes 30 with the surface of theband, it follows that the pressure of the scraper can be adjusted to anydegree of fineness, so that allowance can be made for the particularconditions existing at the time, particularly the sensitiveness or otherstate of the surface to be treated.

In the operative position (see Fig. 1) the bars are so adjusted andpositioned with respect to the band that one bar 22 removes the liquidfrom the upper surface of the band l3 to be treated so that it then runback as shown at 30 over this surface into the bath I I. The scraper 2|removes the liquid from the underside of the band, theliquid fallsdownwards and passes at 3| on to a suitable drip pan 32, which returnsit 5 to the bath H. In this way, most of the liquid carried up by theband l3 out of the bath II can be recovered without there being any riskof any appreciable quantity of liquid passing out of the bath ll intothe bath l2.

By constructing the scraper with two bars arranged at a distance fromeach other, the sensitive band is at the same time prevented from beingsqueezed as it might be if as is otherwise usual, the two scraper rollsarranged opposite 66 each other are pressed together and against theband lying between them.

In comparison with the known scraper rolls there is another advantage,namely that the cost of'manufacture of the new scraper is considerablyreduced, as the parts do not require to run exactly round as in theknown scraper rolls, and therefore do not require such accurateadiustment, on the contrary it sufiices to provide the bars with asmooth surface and drop them loosely into their bearings. At the sametime the scraper according to this invention permits 01 the scraperrolls being conveniently cleaned while it is at work, should any matterout of the baths become deposited on the surfaces of the bars. In suchcase it will suffice to bring the scraper into the position shown inFig. 2, and clean the bars off, which operation, in the case of glassbars, can be carried out with an acid.

The scraper can be fixed in the operative position by any desired means,say for example by providing one or both flanges, e. g. 26, on theoutside with a series of openings 38 into which a bolt or a pin can bepushed. Means may also be provided in order to resiliently hold the barsin position, for example the spindle 36 being provided with an adjustingspring 31.

Since certain modifications in the apparatus which embodies theinvention may be made withfor resiliently holding said scraper in wipingposition.

2. In an apparatus for treating sheets or films with a liquid, thecombination of a plurality of treating vats containing liquids, means topass a sheet or film successively through said vats in contact with saidliquids, a scraper positioned to contact the sheet or film as it passesfrom one vat to the next, said scraper comprising a pair of rotatablecylindrical wiping members, means to support said members in spacedparallel relation, said supporting means adapted to be rotated to bringsaid members into wiping contact with a. sheet or film passingtherebetween, and means adjustable for fixing said scraper in wipingposition, and means positioned below the scraper for catching liquidscraped from said sheet or film and for returning said liquid to the vatfrom. which the sheet or film has just issued.

3. In an apparatus for treating sheets or films with a liquid, a scrapercomprising a pair of freely rotatable cylindrical wiping members, meansto support said members in spaced parallel relation, said supportingmeans adapted to be rotated to bring said members into wiping contactwith a sheet or film passing therebetween, and means for resilientlyholding said scraper in wiping position.

4. In an apparatus for treating sheets or films with a liquid, thecombination of a plurality of treating vats containing liquids, means topass a sheet or film successively through said vats in contact with saidliquids, a scraper positioned to contact the sheet or film as it passesfrom one vat to the next, said scraper comprising a pair of rotatablecylindrical wiping members, means to support said members in spacedparallel relation, said supporting means adapted to be rotated to bringsaid members into wiping contact with a sheet or film passingtherebetween, and means adjustable for fixing said scraper in wipingposition, and a plate positioned below said scraper and adjusted as toits form to the path of the sheet or film, said scraper in its wipingposition and said plate being in co-operative relation for catchingliquid scraped from the said sheet or film and for returning said liquidto the vat from which the sheet or film has just issued without anydripping of liquid to a surface of the film or sheet just cleaned, orwithout contaminating any following bath from liquid carried along bythe sheet or film of the first bath.

ERNEST BLEIBLER.

